Cold planers, also referred to as road mills or scarifiers, are milling machines that typically include a frame propelled by tracked drive units. The frame supports an engine, an operator station, and a milling drum among other components. The milling drum, fitted with cutting tools, is rotated through a suitable interface by the engine to break up the surface of the roadway. The roadway material is deposited by the milling drum onto a lower or first conveyor for removal from the underside of the machine. The first conveyor may have a lower end to receive the material and transfer to an upper end. The material is then transferred from the upper end of the first conveyor onto a second conveyor. The second conveyor transports the material away from the machine and over a nearby haul truck. The material travels up the second conveyor and falls off the end into the haul truck for transportation away from the jobsite.
Typically, the second conveyor is configured to transport the material at a rate and/or trajectory dependent upon vehicle dynamics such as engine speed, from the machine into a haulage machine such as the haul truck. However, substantial change in the rate and/or trajectory may not be generally desirable in view of inability to control the material being delivered to the haul truck. Furthermore, the material may fall outside the haul track thereby creating need of labor and time resources that are desired to be avoided.
For example, U.S. Pat. No. 7,077,345 (hereinafter referred to as '345 reference) discloses a horizontal grinder. The '345 reference discloses a grinder having a grinding structure and upper and lower feed conveyors for feeding material toward the grinding structure, wherein the upper feed conveyor is positioned above the lower feed conveyor. Further, the grinder also includes a power source for powering the grinding structure. A controller configured for controlling the speed of at least one of the lower and upper feed conveyors in proportion to an operating characteristic of the power source.